C : Program for creating structure and accept structure members using structure pointer

Program:

//c program for creating structure and accept structure members using structure pointer

#include<stdio.h>

struct student
{
    int rollno;
    char class[20];
};

int main()
{
    struct student std;
    struct student *ptr = &std;

    printf("Enter roll number of student :");
    scanf("%d", &ptr->rollno);

    printf("Enter class of student :");
    scanf("%s", ptr->class);


    printf("\nRoll number of student : %d\n", (*ptr).rollno);
    printf("class of student :%s", (*ptr).class);

    return 0;
}

Output :

output

Explanation :

This C program demonstrates the use of structures and structure pointers to accept and display student information. Here's an explanation of the program:

1. It starts by including the standard input-output library using `#include <stdio.h>`.

2. A structure named `student` is defined, which contains two members:
 - `rollno` of type integer to store the roll number.
- `class` of type character array (string) with a maximum length of 20 characters to store the class name.

3. Inside the `main` function:
- An instance of the `student` structure is declared as `std`.
- A pointer to a `student` structure named `ptr` is created, and it's initialized with the address of the `std` structure.

4. The program prompts the user to enter the roll number of the student using `printf`, and then it reads the input into the `rollno` member of the structure using `scanf` with the `&` operator: `scanf("%d", &ptr->rollno);`.

5. Next, the program prompts the user to enter the class of the student using `printf`, and it reads the input into the `class` member of the structure. Note that in this case, you don't need the `&` operator since `ptr->class` is already an array: `scanf("%s", ptr->class);`.

6. Finally, the program prints the entered information using `printf`. It displays the roll number and class of the student by accessing the structure members through the pointer using the `->` operator: `printf("\nRoll number of student : %d\n", (*ptr).rollno);` and `printf("Class of student: %s", (*ptr).class);`.

7. The program ends by returning 0, indicating successful execution.

This program essentially allows you to create a student structure, accept information for a student, and then display that information using a structure pointer.

(Explanation credit — Chat GPT)